Hydraulic controlling device in machines for die casting under pressure



Sept. 24, 1940.

J. VONTOBEL ET AL HYDRAULIC CONTROLLING DEVICE IN MACHINES 'FQR DIE CASTING UNDER PRESSURE Filed lay 27, 1938 I rs Sheets-Sheet 1 I I Q lelokdchner I I l-ve-tars Q- Sept. 24, 1940. VQ NTOBEL AL 2,216,059 HYDRAULIC CDNCI'ROLLING DEVICE IN MAQHINES FOR DIE CASTING UNDER PRESSURE Filed May 27, 1938 v5 sheets-sheet 2' era MAM V 1 1635641061761 /n rnar J. voNTdBEL tr AL se g; 24, 1940.

HYDRAULIC CONTROLLING DEVICE IN MACHINES FOR DIE CASTING UNDER PRESSURE Filed lay 27, 1938 s sheets -sheet s Patented Sept. 24, 1940 ,UNITE STATES 'HYDRAULIC CONTROLLING DEVICE IN MA- CHINES FOR DIE CASTING UNDER PBES- I I SURE Jakob'vontobel, Teufenthal, and Karl L'ebkiichner, Granichen; Switzerland, assignors to the firm Injecta. Aktiengesellschaft, Teufenthal, I Canton of Argovie, Switzerland Application May 27, 1938,-Serial No. 210,528

In Switzerland May 29, 1937 3 Claims. (01.22-68) The present invention relates to a hydraulic controlling device in machines for die casting under pressure, of the kind, where a reciprocate 1o vice ofthe reciprocating movements of the cam shaft.

v The annexed drawings show as an example an embodiment of the invention.

Figs. 1a and lb represent together a diagram- 15 matic view of therequired controlling mechanisms,

Figs. 2 to '7 relate to the reversing -gear, Figs. 2 and 3 are cross sections on the line 2-2 in Fig. 6, showing the parts in different posi- 20 tions,

Figs. 4 and5 are cross sections on line 4-4 in Fig. 6 showing the parts in different positions, Fig. 6 is a longitudinal central section on the line 66, Fig. 3, and 25 Fig. 7 a lateral view.

According to Figs. la and lb a distributing plate I carries a main cock 3 controlling the main pressure conduit 2 fed by an accumulator not shown. From this main cock are branched 30 off firstly aconduit 4 controlled by the valves 6 and 1 for the opening of the mould closing cylinder, secondly a conduit 8 leading to one end of a cylinder 9 controlling a knock off device for the castings and thirdly a distributing conduit Ill 5 which feeds on one side a conduit ll leading .to the pressure cylinder 12, two conduits l3 leading to the buffer cylinders lliwhich push off the left hand half of the mould l5 carried by plate l4 from the injecting spout not shown and a 40 fourth conduit [1 leading to the controlling cyl- On the other side from this distributing conduit H) are inder l8 of the camshaft l9.

branched off two conduits 23,-2! feeding the valves 23, 24 and .23 controlled by a hand operated 45 double lever 22, 22' serving as starting and stopping member. Valve 23 is connected by a conduit 25 to the controlling valves 26, 25. oper-- ated by the cam shaft l9 and relieve valve 24 feeds a distributing pressure conduit 21 whereas valve 23' will operate the communication between the pressure conduit 25 admitting of regulation with a drain conduit 34. From this distributing conduit 21. are branched off the following pressure conduits, firstly a conduit leading to the controlling valve 23 of the buffer cylinders 29 which have to stop the carrier plate of the right hand half of the mould for the purpose. of withdrawing the-cores; secondly a conduit leading to the controlling valves 30', 30 of one side of a so called multiplicating cylinder 3|, 5

thirdly a conduit leading to the controlling valves 32', 32",32' feeding the other side of'- the cylinder of the knock off device and the other sides of the multiplicating cylinder and the mould closing cylinderand-fourthly a. conduit leading to the controlling valve 33' of the pressure cylinder l2..

Besides the main pressure conduit 2 there is also a collecting conduit 34-without pressure serving as return conduit into a not represented reservoir feeding the punip. The following conduits are connected with this collecting conduit: a conduit 35 coming from the relieve valve 23', a conduit 36 coming from the relieve valve and four conduits 31, 38, coming from the 30- relieve valves 30", 32", 33" and I.

With exception of the buffer cylinders all other operating cylinders, to wit: pressure cylinder; closing cylinder, multiplicating cylinder 'and controlling cylinder are arranged as dif- 25 ferential cylinders. v

An extension-of the piston rod 40 of the controlling cylinder carries a'rack 4| imparting to pinion 42 fast to the-cam shaft an oscillating movement of 180 when differential piston 43 30 is operated by means of the pressure conduits l1 and 4.4. A regulating valve 45 is provided in the pressure conduit 44 and a regulating valve 46 in the relieve conduit .36 before the relieve valve 26'". In the pressure conduit system must be 35 distinguished the conduits branched off directly from the distributing conduit in all fed with constant pressure and the conduits branched of! from thevalves 23, 24 fed with pressure admitting. of regulation. Now valves 26', 25" transmit such a regulated pressure operating on the larger surface of the differential piston 43 an moving, while valve 26' and regulating cock 45 are opened, the rack 4| downwards and the cam shaft in an anticlockwise direction. If however 45 valve 26' is shut and valve 26" opened the larger surface of piston 43 will be relieved by-conduit 35 and the pressure of conduit l1 will rotate, the

cam shaft in a clockwise direction. This alternate rotation is operated bya pivoted lever 41 5 .v

. This lever 41 pivotally held by an axis 49.and arranged on a plate 48 bears by means of an ad- ;justable screw upon the stem 5| of valve 26 and rests with its one end on a helical spring 52. On the other side of pivot 49 lever-41 5 carries an adjustable screw 53 which may come into contact with the stem of the relieve valve 26"- and carries at its other end a roller operated by a ,cam nose I common to the two relatively fixed cam disks 8" and 82 (Figs. 2 to 7) rotatably mounted on the cam shaft [9 and controlling the oscillations of lever 41' The cam disks 82 and 82 form parts of the reversing gear illustrated by Figs. 2 to '7 as will be hereinafter more fully described.

The valves 23, 23' and 24 are controlled in a like manner by the handoperated pivoted lever 22 and lever 22' rigidly connected therewith. When valve 23 isopened by lifting the adJustable screw 56 and when by the liquid pressure and by lowering the adjusting screw 51 valve 23-! has been closed, the pressure in conduit 25 will move. the controlling piston 43 downwards. At the same time'bylifting the adjusting screw 58 the distributing conduit 21 will be put under pressure. If the pivoted levers 22, 22 are in a median position valves 23 and 24 will be closed and relieve valve 23' remains closed likewise.

V tween piston 82 and valve 23 is shut off and per- The liquid under pressure inconduit 25 between valve 23 and piston 43 is therefore cut off and prevents any further movement of controlling piston 43. Likewise in this median position of the pivoted levers .the distributing conduit becomes relieved from pressure, and all movements of the machine controlled by this conduit are stopped at once.

By commuting the position of lever 22, 22' into a third position relieve valve 23' will be opened, while valves 23 and 24 remain'closed. The constant pressure in conduit il operating on the smaller surface of controlling piston 43 will move now piston 43 upwards, since the liquid enclosed between valve 23 and piston 43 can pass through the opened valve 23' and conduit 35 into the drain conduit 34. By the upwards movement of piston 43 also the direction of revolution of cam shaft i9 will be reversed and therefore the machine be'restored to its initial position.

The manner of distributing the available'working pressure combined with the manually oper-- ated lever permits, after having stopped at once all movements of the machine,.to continue the movements of the machine at once or to restore the initial position by a simple commuting of said manual lever. I

By conveniently adjusting the regulating valves 45, 46 the cross section of conduits 38, 44 leading to the controlling piston 43 and thereforealso the speed of its movement may be regulated continuously.

Figs. 1a and lb represent the position of parts at the moment after casting, that is shortly before the reversing of, the machine to open the mould. V

The controlling of the valves by the cam shaft is operated by cam 59 in a like manner as described for cam 82. A single valve 28 operated by the adjusting pin 63 suflices for the first pivoted lever 8i which is' arranged with the controlling cylinder "IS on the same plate 50 and serves for controlling the buffer pistons 62. While this valve remains closed also the pressure liquid bemits a return of the buii'ers only, when the valve is opened by adjusting pin 63. This occurs at the opening stroke to withdraw the cores. At the closing stroke said valve acts as a nonreturn valve. I

The pressure conduit 54 controlled by this valve 23 is branched into two conduits 54' for the two bufier cylinders 23. Pivoted lever 38 controls the two valves 32' and 32".. The first transmits the pressure of conduit 21 through conduits 58' and 63 to the larger piston surface of pressure cylinder and effects the closing of the mould, while valve 32" serves as relieve valve for the larger piston surface. At thesame time through the opened valve 32' the working pressure is transmitted through conduit to the larger piston surface of a knock of! device 1!, intended to knock off the castings expelled from the mould. With a view of obtaining a higher closing pressure of the mould a multiplicator 3| has been provided having also a differential piston. Pivoted lever 55 controls this cylinder through the valves 30' and 30", the latter serving as relieve valve of the pressure acting upon the larger pistonsurface and valve 30 transmit ting the pressure of conduit 21 to the pressure conduit 61 of the multiplicator. The smaller piston surface transmits the pressure considerably increased by the difference of area of the two piston surfaces to the larger piston surface of cylinder 5 through conduit 58. A non return valve 32" prevents a transmitting of the increased pressure through the open valve 32 to the pressure conduit 21.

The fourth pivoted lever 12 controls the pressure conduit 13 acting upon the larger piston surface of the pressure cylinder I2 adapted to operate upon the metal in the mould. Here valve 33" acts as relieve valve, while valve 33, transmits the pressure from conduit 21. The fifth pivoted lever 14 controls the so called con- The multiplicator is operated only when the mould has been closed.

stant pressure fed directly from the distributing conduit. iii-through valve 6, valve 1- serving as relieve valve, and acting upon the smaller piston surface of the closing piston 5'. During the closing of the mould valve 3 is opened and relieve valve closed; so that the pressure actingon the smaller area counteracts the .pressure acting on the larger area. During the pressing valve 6 is closed by cam- 59 while operating the pivoted lever 14 and the relieve valve 1 isopened, so that the smaller piston surface 5' .becomes without.

pressure and the closing pressure becomes increased. The respective pressure chamber of the closing cylinder 5 communicates through an axial bore 16 with the pressure chamber behind the piston 11 of the hydraulic coupling 18 between mould carrier and piston 5, so that through conduit I8 also the hydraulic coupling will be controlled. A cut off valve 18 permits to render this controlling possibility impossible.

According to Figs. 2 to 7 the reversing gear comprises two spring boxes 80 80 keyed to the cam shaft is and rigidly connected with two annular :cams 8H, 3H; besides his two rigidly connected cam disks 82 and 32 are loosely arranged on shaft 19 between said spring boxes. While the spring controlled pawls 84 84 arranged loose on a common axis 83 cooperate with the circumferentially opposed radial teeth 82 and 82* of the cam disks 82 82 the noses of the annular cams 3l M are intended for controlling said pawls by means of laterally projecting cam rollers 84 34 provided on said pawls. Somewhat more than half of the annular hollow inside of the springboxes' are occupied by springs'fl'l, 31" provided respectively with the head pieces 5.5 9. 35 and 38", 36*? serving as pressing members, while catches 88 83 projecting laterally at corresponding points from the opposite sides of the cam disks .32 82 are exagain be changed into an anticlockwise direction.

tended into the still remainingfree spaces of the spring boxes andare adapted for stressing said springs 81 8'! by means of the spring head pieces 86 86 and 86 86.

This reversing gear operates as follows: In both of Figs. 2 and 5, the cam disks 82! and B2 are in the position in which the nose J00 engages the lever downwardly. Shaft l9 now kicked in the counter-clockwise .813 and 88 the abutment 41 and Fig. 5 shows the moment when the reversing gear has closed the valve 26"-and opened the valve 26. Thus, the pressure liquid enters the upper end of the cylinderl8 and the piston 43 and rack 4| move begins its counterclockwise movement carrying therewith the two spring boxes Bil and and the springs-81 and 81 and associated head pieces 86 86 and 86 86 The cam disks 82 82 are prevented from participating in this movement 'by tooth 82 of disk 82 meeting with pawl 84 and after movement of the spring boxes shown in Fig. 5 to that in Fig. 2 the head pieces 86, 86" of springs 81 81* meet'with the catches 88 88 extended into the spring boxes 80 80. The boxes continue rotating and stress thereby said springs until the with the roller 84" disengages the pawl 84 from the tooth 82 as shown in Fig. 3. The camdisks 82 v82 are thus released and kicked suddenly in an anticlockwise direction by the springs 81*, 81 acting on the catches 88 88 so that lever 41 drops with a jerk off of the nose I00 closing thereby valve 26 and opening valve 26' both with a sharp quick action. The piston 43 is reversed 'and the rack 4| rises again and rotates shaft IS in a clockwise direction. This adjustment of the nose I00 and lever 41 is illustrated in Fig. 3. e

The low portions of the cam disks 82 8 2" remote from the nose I00 possesses also a tooth 90 which becomes engaged by the spring con-' trolled pawl 89, Fig. 3, when the cam disks are direction by the phase of operation I9 completes one springs 81 81 In this first of the reversing gear the shaft half of a revolution.

At the beginning of clockwise rotation of the shaft is and spring boxes BB -4i) the disks 82 --82 are held against rotation by the pawl 84 engaging the tooth 82 as shown in Fig. 4. The rotation of the spring boxes continues independently of the disks 82 -82 until thehead pieces 86 and 86 of the spring abutthe catches of the head piece 86 being shown in-Fig. 4.

While shaft i9 continues rotating-in a clockwise direction the springs 81 81 held fast by the catches 88 88 are compressed until the annular cam 8| meets roller 84 and throws pawl 84 out of gear as shown in Fig. 5. By this action the cam disks 8 2 82 will become freed and be kicked clockwise by the compressed springs 81 and 81 from the position shown in Fig. 4 to that of Fig. 5, the nose I00 being sharply forced beneath the end of lever 41 Thereby valve 26" becomes suddenly closed and valve 26. opened and thus the rotation of the shaft I! will -cam and releasing saidcam from the positionannular cam 8" meeting said cam-discs,

Due to the jerk-like opening and closing of the commuting valves this change is effected sudden- What we claim is: I 1. In a hydraulic controlling device in ma- ,chines for die casting under pressure, an-osciling gear driven by the cam-shaft for controlling said member, said reversing gear including an actuating cam for said member and means operable by the cam shaft for alternately applying oppo sitely directed resilient forces movements in opposite directions.

2.- In a hydraulic controlling device in machines for die casting under pressure; an oscillating cam-shaft for operating the valves adapted to control the different working-actions of the machine, a cylinder containing a hydraulically operated piston for driving the cam-shaft, valves for controlling said piston, spring-boxes fixed to said cam-shaft, cam-discs rigidly. connected to each other and loosely arranged on said camshaft and adapted to control said valves, stopping means adapted to stop the cam-discs, annular cams on the outer surface of said spring-boxes, adapted to disengage said stopping means from springs in said boxes and catches laterally projecting from said springs being adapted to be loaded with thehelp of said catches when the cam-discs are stopped and to swing the latter when these are disengaged from the stopping means.

3. In a hydraulic controlling device in ma chines for die casting under pressure, an oscillating cam-shaft for operating the valves adapted to control the different working-actions of the machine, a cylinder containing a hydraulically operated piston for driving the camshaft. valves for controlling said piston and a spring-operated reversing gear arranged to be brought into cam-shaft andadapted to operate said pistoncontrolling valves by Jerks, a main supply conduit for the pressure medium. conduits branched of! from said main supply conduitand leading to the cylinder containing the cam-shaft-driving piston and to a waste-conduit, a distributing conduit branched or! from said main supply conduit and adapted to lead the pressure medium to the other cylindersof the machine, valves adapted to control the supply of'said branched of! conduits and the distributing conduit and a handoperated double-lever for the operating or the said supply-controlling valves, the machine by this double-lever may thus be started, suddenly to said actuatingto perform snap cam-discs, said acting-position by means of the.

stopped 'or returned to the outgoing-position at 

